:root {
  --bg: #0f1419;
  --card: #1a222c;
  --text: #e8eef4;
  --muted: #9aa8b6;
  --accent: #3d8bfd;
  --error: #e35d6a;
  --border: #2a3542;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: radial-gradient(1200px 600px at 20% -10%, #1c2a3a 0%, var(--bg) 55%);
  color: var(--text);
  display: grid;
  place-items: center;
  padding: 1.5rem;
}

.card {
  width: min(420px, 100%);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
}

h1 {
  margin: 0 0 0.35rem;
  font-size: 1.35rem;
  font-weight: 650;
}

.sub {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-size: 0.95rem;
}

label {
  display: block;
  margin: 0.75rem 0 0.35rem;
  font-size: 0.9rem;
  color: var(--muted);
}

input[type="text"],
input[type="password"] {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #121820;
  color: var(--text);
}

button {
  margin-top: 1.25rem;
  width: 100%;
  padding: 0.7rem 1rem;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

.error {
  background: rgba(227, 93, 106, 0.12);
  border: 1px solid rgba(227, 93, 106, 0.35);
  color: #ffb4bb;
  padding: 0.65rem 0.75rem;
  border-radius: 8px;
  margin: 0 0 1rem;
}